#20 Remove file name in single file mode

[froschbrocken]

Most of the time I use SourceCookifier in single file mode. Is it possible to remove the file name from the top of the list in this case? I don't see any reason why it is displayed, since you should know which file you have opened at the moment. It only takes up vertical space and even makes all further entries indented by one level, which takes up horizontal space as well. I would be very thankful if the filename could be removed from the list, so that the tree has one level less.